Manufacture of polymers of cycloolefins by ring-opening polymerization of cycloolefins

ABSTRACT

A process for the manufacture of polymers of cycloolefins by ring-opening polymerization of cycloolefins using a catalyst system which consists of (1) a transition metal salt, (2) an organometallic compound of an element in group IVa and (3) an aluminum halide, provided that, per mole of catalyst component (1), there are present from 0.1 to 100 moles of catalyst component (2) and from 0.1 to 250 moles of catalyst component (3). This process makes it possible to manufacutre polymers of cycloolefins in a particularly advantageous manner.

United States Patent [1 1 Weitz et al.

[451 Feb. 11, 1975 MANUFACTURE OF POLYMERS OF CYCLOOLEFINS BY RING-OPENING VPOLYMERIZATION OF CYCLOOLEFINS [76] Inventors: Hans-Martin Weitz, l7 Wildstrasse,

6710 Frankenthal; Helmut Schwarz,

l7 Grasse Casse, 6700 Ludwigshafen, both of Germany [22] Filed: Jan. 4, 1973 [2]] Appl. No.: 320,846

[52] U.S. Cl. 260/93.1, 252/429 [51] Int. Cl. C08f 5/00 [58] Field of Search 260/93.l

[56] References Cited UNITED STATES PATENTS 3,577,400 5/197] Judy 260/882 3,657,208 4/1972 Judy 260/882 R Primary Examiner-John C. Bleutge Attorney, Agent, or Firm-Johnston, Keil, Thompson & Shurtleff [57] ABSTRACT A process for the manufacture of polymers of cycloolefins by ring-opening polymerization of cycloolefins using a catalyst system which consists of 1) a transition metal salt, (2) an organometallic compound of an element in group Na and (3) an aluminum halide, provided that, per mole of catalyst component (I), there are present from 0.1 to 100 moles of catalyst component (2) and from 0.1 to 250 moles of catalyst component (3). This process makes it possible to manufacutre polymers of cycloolefins in a particularly advantageous manner.

3 Claims, No Drawings teresting,

MANUFACTURE OF POLYMERS OF CYCLOOLEFINS BY RING-OPENING POLYMERIZATION F CYCLOOLEFINS The present invention relates to a process for the manufacture of polymers of cycloolefins by ringopening polymerization of cycloolefins using a catalyst system.

Polymers of this kind have recently become very ine.g. polymers of cyclopentene (1,5- polypentenamers"). Vulcanizates produced from these polymers are characterized by desirable physical properties (high abrasion resistance, slip resistance and elasticity).

It is an object of the present invention to provide a process of the above type which shows advantages over prior art processes of comparable nature.

We have found that this object is achieved in a process for the manufacture of polymers of cycloolefins by ring-opening polymerization of cycloolefins using a catalyst system, when said catalyst system is one consisting of:

l. a transition metal salt,

2. an organometallic compound of an element in group Wu and 3. an aluminum halide, provided that, per mole of catalyst component (1), there are present from 0.1 to 100 moles of catalyst component (2) and from 0.1 to 250 moles of catalyst component (3).

It has been found advantageous to use, per mole of catalyst component (1), from 1 to 50 moles of catalyst component (2) and from 1 to 100 moles of catalyst component (3), and it is particularly advantageous to use, per mole of catalyst component (1), from 2 to 20 moles of catalyst component (2) and from 2 to 50 moles of catalyst component (3).

The following remarks relate to the materials used in the present invention.

The cycloolefins to be polymerized should, as usual, be as pure as possible and in particular contain no catalyst poisons. Suitable compounds for the polymerization are, for example, unsaturated alicyclic compounds, preferably monoolefins, in particular cyclopentene and cyclooctene. The amount of cycloolefm used should be such that the molar ratio of catalyst system to olefin is greater than 1:100.

Particularly suitable transition metal salts (1) are the halides of the transition metals in group Vlb, preferably the (oxy)halides of chromium, molybdenum and tungsten, particularly their (oxy)chlorides. Especially suitable are WCl and MoCl The halides and oxyhalides may be used alone or in the form of mixtures of two or more of said components.

Preferred organomettalic compounds of elements in group [Va used as components (2) are alkyl and aryl lead compounds (e.g. lead tetramethyl and lead tetraethyl) and the corresponding compounds of tin (e.g. tin tetramethyl, tin tetra-ethyl, tin tetrabutyl and tin tetrahexyl) and the total number of carbon atoms in each compound should not exceed 75. Dialkyl tin salts of organic acids (e.g. dibutyl tin dilaurate and dibutyl tin maleate) may also be used.

The aluminum halide used as component (3) is preferably the trichloride, but the tribromide is also suitable on account of its good solubility in organic solvents. Aluminum iodide may also be used. The trihalides may be used alone or in the form of mixtures of two or more of said trihalides.

The process itself may be carried out at temperatures of from 20 to C and preferably from +l0 to +50 C, and at the pressures automatically obtained at the temperature used. it is gnerally convenient to use hydrocarbons as solvents. One suitable solvent is benzene. Saturated hydrocarbons such as cyclohexane and n-hexane may also be used, the risk of alkylation of these solvents by Friedel-Crafts reactions being avoided (Example 2). Before the commencement of polymerization, the cycloolefin should be present in the solvent in the form of a 1 to 50% and in particular 10 to 30% v/v solution. Alternatively, the process may be carried out without added solvent, in which case the cycloolefin itself acts as solvent. To avoid polymer solu tions of unduly high concentration, it is often convenient, particularly in the last-named case, to stop polymerization at a suitable stage. This may be effected in conventional manner by the addition of proton-active compounds such as alcohols, e.g. methanol, or phenols, e.g. 2,6-di-t-butyl-p-cresol. isolation of the polymers from their solutions may also be effected in conventional manner, particularly by precipitation using, for example, alcohols (e.g. methanol).

Polymerization probably proceeds according to the following scheme (illustrating the use of cyclopentene):

NMR analyses of cyclopentene polymers showed the correct ratio of vinyl, ally] and aliphatic protons for the above structure (2:4:2) within the normal margin of error (cf. Example 1). Where cyclooctene is used (Example 3), the NMR analysis of the polymers also showed the correct ratio of vinyl, allyl and aliphatic protons (224:8) for the above scheme. The polymer of cyclooctene is less elastic than that of cyclopentene however.

All operations are carried out with rigid exclusion of air and moisture. The olefins and solvents are purified and dried thoroughly, and the WC l is freed from impurities by sublimation.

EXAMPLE 1 To a suspension of 0.3749 g (2.8116 millimoles) of AlCl (anhydrous) in ml of benzene, placed in a flask, there are added at room temperature 0.60629 g (1.8744 millimoles) of Pb(C l-l and the mixture is stirred for 10 minutes. 4.686 ml of a 0.05M solution of WCI in benzene (0.2343 millimoles) and 34.06 g (0.5 moles) of cyclopentene are then added to cause the temperature to rise by about 5 C. The molar ratio of WC1 to Pb(C H to .AlCl to cyclopentene is 1:8:l2z2133.

After a further 30 minutes, the reaction is stopped by the addition of 10 ml of a 6% w/w solution of 2,6-d-tbutyl-p-cresol in an 80/20 v/v mixture of benzene/methanol or by the addition of 10 ml of methanol. The viscous solution is diluted with 300 ml of benzene and added dropwise to 4 1 of methanol to cause precipitation of the polymer. The polymer is boiled with methanol and then dried in a vacuum drying cabinet at 40 C. There are thus obtained 12.95 g, (38% of theory) of transparent elastic polymer. The structure of the polymer is confirmed for example by its NMR spectrum giving a proton ratio of vinylzallylzaliphatics of l.86:4.0:2.0.

On precipitation of the polymer and distillation from benzene, methanol and unreacted cyclopentene, there are found Friedel-Crafts alkylation products in the resulting organic residue.

EXAMPLE 2 Example 1 is repeated except that cyclohexane is used as solvent, the WCl being dissolved in 50 ml of the 180 ml of cyclohexane used, and an elastic polymer is also obtained. In this case, however, no Friedel- Crafts alklation products are found.

EXAMPLE 3 There is obtained a polymer having a proton ration (NMR spectrum) of vinyl, allyl and aliphatic protons of 1.82:4.0:8.4. This product has somewhat weaker elastic properties than the polymer of cyclopentene.

We claim:

1. In a process for the manufacture of polymers of cyclopentene by ring-opening polymerization of cyclopentene using a catalyst system, wherein the catalyst system used is one consisting of 1. the transition metal salt WCI 2. the organometallic compound Pb(C H and 3. a suspension of AlCl and wherein per mole of catalyst component 1 there are present from 0.1 to moles of catalyst component (2) and from 0.1 to 250 moles of catalyst component (3), the improvement which comprises: mixing a suspension of AlCl with Pb(C H and thereafter adding WCI followed by the addition of cyclopentene.

2. A process as claimed in claim 1, wherein the molar ratio of catalyst system to cyclopentene is greater than 3. An improved process as in claim 1, wherein AlCl is mixed with Pb(C l-l for ten minutes before WCl is added.

UNITED STATES PATENT AND TRADEMARK OFFICE QETIHCATE 0F CORRECTION PATENT NO. 3, 865,800 DATED February 11, 1.975

|NVENTOR(5) 3 Hans-Martin Weitz et a1.

It rs certified that error appears in the ab0ve-rder|tified patent and that said Letters Patent are hereby corrected as shown below:

In the Heading, insert-- [30] January 11, 1972 Germany Signed and Sealed this A ttcst:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner of Ian'nls and Trademarks i I m 

1. IN A PROCESS FOR THE MANUFACTURE OF POLYMERS OF CYCLOPENTENE BY RING-OPENING POLYMERIZATION OF CYCLOPENTENE USING A CATALYST SYSTEM, WHEREIN THE CATALYST SYSTEM USED IS ONE CONSISTING OF
 1. THE TRANSITION METAL SALT WCL6,
 2. THE ORGANOMETALLIC COMPOUND PB(C2H5)4 AND
 2. A process as claimed in claim 1, wherein the molar ratio of catalyst system to cyclopentene is greater than 1:100.
 2. the organometallic compound Pb(C2H5)4 and
 3. a suspension of AlCl3, and wherein per mole of catalyst component (1), there are present from 0.1 to 100 moles of catalyst component (2) and from 0.1 to 250 moles of catalyst component (3), the improvement which comprises: mixing a suspension of AlCl3 with Pb(C2H5)4 and thereafter adding WCl6 followed by the addition of cyclopentene.
 3. A SUSPENSION OF ALCL3, AND WHEREIN PER MOLE OF CATALYST COMPONENT (1), THERE ARE PRESENT FROM 0.1 TO 100 MOLES OF CATALYST COMPONENT (2) AND FROM 0.1 TO 250 MOLES OF CATALYST COMPOENT (3), THE IMPROVEMENT WHICH COMPRISES: MIXING A SUSPENSION OF ALCL3 WITH PB(C2H5)4 AND THEREAFTER AFDING WCL6 FOLLOWED BY THE ADDITION OF CYCLOPENTENE.
 3. An improved process as in claim 1, wherein AlCl3 is mixed with Pb(C2H5)4 for ten minutes before WCl6 is added. 